It's thought that when the stress system turns on and off, on and off,…
It's 8:15 a.m., and the meeting you're supposed to be running started 15 minutes ago, and your boss would be on the phone chewing you out except that your phone has died, which is why you can't call for someone to come fix your flat tire. Here you are, stuck at the side of the freeway, a sitting duck to get rear-ended.
That's what's going on in your car. But what's going on in your brain?
Stress, that's what. Your sympathetic nervous system has released a surge of norepinephrine, famously preparing you for "fight or flight" (both of which have appeal in your present circumstances). And your so-called hypothalamic-pituitary-adrenal axis has released a cascade of hormones culminating in a burst of cortisol, the "stress hormone," into your blood.
Overall, your stress response is designed to make you extra fast, extra strong, extra sharp for a little while, just long enough to get yourself out of some imminent physical danger (a mountain lion wants to eat you or a tree branch is about to smash your head), explains Jiongjiong Wang, an associate professor of neurology at UCLA.
But the response is not always useful in coping with much of the stress you feel day in and day out, over tires that go flat, friends who give you grief, bosses who make unreasonable demands. Not to mention the stress you feel over things that never even happen. Our big-brained species has "progressed" to the point where we often imagine — and obsess over — dire fates. (Oh dear! The wind is blowing like crazy, which means my power is going to go out, which means I won't have my computer, which means my project is going to be late, which means I'm going to lose my job.)
"For the vast majority of beasts on this planet, stress is about a short-term crisis, after which it's either over with or you're over with," Stanford neurology professor Robert Sapolsky wrote in his book about stress and stress-related diseases, "Why Zebras Don't Get Ulcers." "When we sit around and worry about stressful things, we turn on the same physiological responses — but they are potentially a disaster when provoked chronically."
It's thought that when the stress system turns on and off, on and off, on and off repeatedly, controls eventually break down, says Nim Tottenham, an assistant professor of psychology at UCLA. "You start to get a deregulation of the system." At first, this tends to make people super reactive to any stressful incident, but sometimes, after too long, their systems may become so overwhelmed that they don't even respond adequately anymore.